EPIDEMIOLOGYNAFLD is now recognized as one of the most common causes of minor serum aminotransferase elevations and chronic liver diseases in developed countries such as Europe and America, and the prevalence of NAFLD
ObjectiveAccumulation of free fatty acids (FFAs) in hepatocytes induces lipotoxicity, leading to non-alcoholic fatty liver disease (NAFLD). This study aimed to investigate the underlying mechanisms by which FFA contributes to the pathogenesis of NAFLD via the regulation of 3-mercaptopyruvate sulfurtransferase (MPST), a key enzyme that regulates endogenous hydrogen sulfide (H2S) biosynthesis.DesignHepatic MPST expression was evaluated in mice and patients with NAFLD. A variety of molecular approaches were used to study the effects of MPST regulation on hepatic steatosis in vivo and in vitro.ResultsIn vitro treatment of hepatocytes with FFAs upregulated MPST expression, which was partially dependent on NF-κB/p65. Hepatic MPST expression was markedly increased in high fat diet (HFD)-fed mice and patients with NAFLD. Partial knockdown of MPST via adenovirus delivery of MPST short hairpin RNA or heterozygous deletion of the Mpst gene significantly ameliorated hepatic steatosis in HFD-fed mice. Consistently, inhibition of MPST also reduced FFA-induced fat accumulation in L02 cells. Intriguingly, inhibition of MPST significantly enhanced rather than decreased H2S production, whereas MPST overexpression markedly inhibited H2S production. Co-immunoprecipitation experiments showed that MPST directly interacted with and negatively regulated cystathionine γ-lyase (CSE), a major source of H2S production in the liver. Mechanistically, MPST promoted steatosis via inhibition of CSE/H2S and subsequent upregulation of the sterol regulatory element-binding protein 1c pathway, C-Jun N-terminal kinase phosphorylation and hepatic oxidative stress.ConclusionsFFAs upregulate hepatic expression of MPST and subsequently inhibit the CSE/H2S pathway, leading to NAFLD. MPST may be a potential therapeutic target for NAFLD.
Background and Aims: The clinical significance of hepatic steatosis in chronic hepatitis B infection (CHB) is unclear. The aims of this study were thus to investigate the prevalence and risk factors for hepatic steatosis in patients with CHB and its relationship with liver injury. Methods: Consecutive patients with biopsy-proven CHB at Hangzhou Sixth People's Hospital between January 2005 and June 2007 were included. Patients co-infected with other viruses or suffering from liver disease of any other cause were excluded. Liver steatosis, necroinflammation and fibrosis were assessed by both Brunt and Scheuer classifications. Results: A total of 1915 patients (1497 men) with a mean age of 31 Ϯ 9.5 years were analyzed. Hepatic steatosis was present in 260 (14%) patients. The steatosis involved < 33% of hepatocytes in 90% of cases, and was more frequent among men than women (15% vs 8%, P < 0.001). Two-thirds (178 of 260) of patients with steatosis were hepatitis B e antigen (HBeAg)-positive, but there was no correlation with either serum HBeAg status or hepatitis B virus DNA titer. Degree of inflammation and fibrosis were more mild among those with steatosis than those without. Multivariate analysis showed that steatosis was independently associated with body mass index, serum triglyceride, apolipoprotein B, uric acid, and fasting blood glucose. However, fibrosis was only independently associated with age and inflammatory grade, and the latter associated with viral load and fibrosis stage. Conclusions: Hepatic steatosis is common in CHB, it is associated with metabolic factors not viral ones, and does not appear to affect the severity of liver disease.
Non-alcoholic fatty liver disease (NAFLD) is an important health issue worldwide. We aimed to develop a simple model to determine the presence of NAFLD in a Chinese population. A cross-sectional study with 9602 subjects was conducted. Potential predictors were entered into a stepwise logistic regression analysis to obtain the model. We used 148 patients with liver biopsy to validate this model. The model, named the ZJU index, was developed based on body mass index (BMI), fasting plasma glucose (FPG), triglycerides (TG), and the serum alanine aminotransferase (ALT) to serum aspartate transaminase (AST) ratio. The area under the receiver operating characteristic curve (AUROC) of the ZJU index to detect NAFLD was 0.822. At a value of <32.0, the ZJU index could rule out NAFLD with a sensitivity of 92.2%, and at a value of >38.0, the ZJU index could detect NAFLD with a specificity of 93.4%. In patients with liver biopsy, the ZJU index could detect steatosis with good accuracy, with an AUROC of 0.896. This study revealed that the ZJU index is a helpful model to detect NAFLD for community physicians in China. It was validated not only by a validation cohort but also by pathological data.
An optimization strategy based on the Roadmap concept is supposed to improve the clinical outcomes of patients with suboptimal antiviral response. The aim of this study was to prove the concept with a multicenter, open-label, randomized, controlled study. In all, 606 hepatitis B e antigen (HBeAg)-positive, nucleos(t)ide-naive chronic hepatitis B patients were randomized to the Optimize or Mono group. Patients in the Optimize group were treated with telbivudine for 24 weeks, after which those suboptimal responders with HBV DNA 300 copies/ mL at week 24 received telbivudine plus adefovir until week 104, while the early virological responders continued telbivudine monotherapy. Patients in the Mono group received telbivudine monotherapy. All patients with telbivudine monotherapy had adefovir added if viral breakthrough developed. Sixty-eight percent (204/300) of patients in the Optimize group had adefovir added due to suboptimal response. At week 104, compared to the Mono group, more patients in the Optimize group achieved HBV DNA <300 copies/ml (76.7% versus 61.2%, P < 0.001) with less genotypic resistance (2.7% versus 25.8%, P < 0.001). The rates of HBeAg seroconversion and alanine aminotransferase (ALT) normalization were comparable between the two groups (23.7% versus 22.1%; 80.7% versus 79.2%). For week 24 suboptimal responders, telbivudine plus adefovir showed an additive antiviral potency, with 71.1% achieving virological response at week 104 and only 0.5% developing genotypic resistance, compared with 46.6% who achieved virological response and 37.8% who developed genotypic resistance with telbivudine monotherapy. Both treatment regimens were well tolerated, with an observed persistent increase of the glomerular filtration rate. Conclusion: For suboptimal virological responders to telbivudine at week 24, adjusting the treatment strategy is recommended. Adding adefovir can benefit these patients with additive antiviral potency and low resistance without increased side effects. (HEPATOLOGY 2014;59:1283-1292 Abbreviations: ALT, alanine aminotransferase; CHB, chronic hepatitis B; eGFR, estimated glomerular filtration rate; HBeAb, hepatitis B e antibody; HBeAg, hepatitis B e antigen; HBsAb, hepatitis B surface antibody; HBsAg, hepatitis B surface antigen; HBV, hepatitis B virus; IFN, interferon; ITT, intention to treat; LLOD, the lower limit of detection; LOCF, last observation carried forward; MDRD, Modification of Diet in Renal Disease; NUC, nucleos(t)ide analog; PCR, polymerase chain reaction; SAE, serious adverse event; ULN, upper limit of normal.From the
Based on the severity of liver fibrosis, low or high-risk profile of developing end-stage liver disease was present in nonalcoholic fatty liver disease (NAFLD). However, the mechanisms inducing transition from mild to advanced NAFLD are still elusive. We performed a system-level study on fibrosing-NAFLD by weighted gene co-expression network analysis (WGCNA) to identify significant modules in the network, and followed by functional and pathway enrichment analyses. Moreover, hub genes in the module were analyzed by network feature selection. As a result, fourteen distinct gene modules were identified, and seven modules showed significant associations with the status of NAFLD. Module preservation analysis confirmed that these modules can also be found in diverse independent datasets. After network feature analysis, the magenta module demonstrated a remarkably correlation with NAFLD fibrosis. The top hub genes with high connectivity or gene significance in the module were ultimately determined, including LUM, THBS2, FBN1 and EFEMP1. These genes were further verified in clinical samples. Finally, the potential regulators of magenta module were characterized. These findings highlighted a module and affiliated genes as playing important roles in the regulation of fibrosis in NAFLD, which may point to potential targets for therapeutic interventions.
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